India thrashed South Africa by 8 wickets at The Oval on Sunday to qualify for the semi-finals. The defending champions were in top form in all departments of the game.
Bowlers and fielders helped India restrict the Proteas to 191 all out and in the run chase, Shikhar Dhawan and Kohli's half centuries were the high points.
Speaking to the media after the victory, Kohli said AB de Villiers' (16) run out by Hardik Pandya and Mahendra Singh Dhoni was the turning point in the must-win contest. India effected two run outs in successive overs, removing De Villiers and David Miller as South Africa collapsed from 140/2 to 191 all out.
"If you get two run outs pretty quickly, then the mindset totally changes," Kohli said.
"As a captain, you have to understand where the game is heading after that. We only wanted to go for wickets because we understood now they are probably hesitating in going for their shots, and we've got in attacking fielders, and we asked the bowlers to make them play difficult shots.
"So that paid off, we were able to close the game out, and it was really good for us. And as I said getting their big hitters early was a bonus.
"I think initially before AB got run out, he did really well and Faf and AB were rotating it really well. I think his run out could be the turning point, and David Miller's; he's a very dangerous player, as well. They can drag the team up to 260, 270 from any sort of situations. Yeah, I think those two run outs were the turning point today," he added.
India are set to face Bangladesh in the 2nd semi-final on Thursday (June 15) at Edgbaston, Birmingham.